volteer: Disable rtc and rtc_alarm commands on Zephyr
volteer: Disable rtc and rtc_alarm commands on Zephyr

Disable the rtc and rtc_alarm commands on Zephyr to atch the Chromium EC
configuration.

Flash savings with this CL stack: 10136 bytes
RAM savings: 4096 bytes

RO image size before this CL stack:
Memory region         Used Size  Region Size  %age Used
           FLASH:      241244 B       512 KB     46.01%
            SRAM:       61392 B        62 KB     96.70%
        IDT_LIST:          0 GB         2 KB      0.00%

RO image size after commands disabled
Memory region         Used Size  Region Size  %age Used
           FLASH:      231108 B       512 KB     44.08%
            SRAM:       57296 B        62 KB     90.25%
        IDT_LIST:          0 GB         2 KB      0.00%

BUG=b:181794644
BRANCH=none
TEST=make buildall, zmake testall
TEST=Boot zephyr-ec on Volteer

Signed-off-by: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>
Change-Id: I17e29afa562b3f9bfb2271dc60e12807481c7203
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2737546
Commit-Queue: Jack Rosenthal <d3f605bef1867f59845d4ce6e4f83b8dc9e4e0ae@chromium.org>
Reviewed-by: Jack Rosenthal <d3f605bef1867f59845d4ce6e4f83b8dc9e4e0ae@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec